1. Field of the Invention
The present invention relates to a solid state image pickup element, and particularly to an interpolation technique for improving the pseudo resolving power of the element.
2. Description of the Prior Art
For example, the resolving power of an object image formed at a one-dimensional line image pickup device having electric charge accumulation and conversion elements, such as C.C.D's (charge coupled device) and B.B.D's (bucket brigade devices) and an electric charge transfer arrangement is determined by the number of light receiving elements forming the image pickup line or plane. Means for obtaining a high resolving power artificially with a limited number of light receiving elements, particularly by employing an interpolation between outputs of light receiving elements (picture elements) are known. For example, a device described in U.S. Pat. No. 4,148,059 performs interpolation of picture element outputs by providing a circuit with a memory element for memorizing picture element outputs, a delay element, a differential amplifier and an integration circuit, etc. at a part other than the image pickup element. This device has the shortcoming that these constituent elements are of a large scale. Thus, it is difficult to mount them within the same tip with a solid state image pickup element.